According to police, about 12:15 p.m. Tuesday, Mahomes approached three men in the 7400 block of South Champlain, pulled out a gun, and fired numerous shots. Devin Common, 27, died at the scene, and two other men, 27 and 30, were taken to a local hospital.

Mahomes told officers that he lives in the 1300 block of West Sixth Street, a Chicago Police spokesman said.

Law officers in Lee and Whiteside counties said they have not had contact with the teen, and Dixon High School Principal Mike Grady said Mahomes is not registered at the school.